Lamp holders

ABSTRACT

This invention relates to improvements in lamp holders and assembly of lamp holders and edge-lighted panels. In the embodiment illustrated, the lamp is housed in a lamp positioner having conformations to hold the lamp leads with a given orientation relative to the filament of the lamp. These conformations, and the lamp leads they hold, fit in complementally formed recesses in a light-receiving member or light filter in engagement with conductor leads embedded in the light receiver and exposed at those complementary formed conformations. The light receiver is provided with a skirt forming a recess within which the lamp positioner is housed. The recess of the light receiver is closed by an end cap of which bears, through a bias spring, upon the lamp positioner to insure contact between the lamp leads and the conductor leads of the light receiver. An incompletely metallized layer of material overlying the light receiver reflects some of the light emanating from the lamp and permits passage of other light.

United States Patent 3,077,535 2/1963 Dupree [72} lnventor Gerald A. Curl 240/1 X o ge,calif 3,120,350 2/1964 Mvenz 240/1 X PP No 26,140 Primary Examiner-Samuel S. Matthews Flled May 1969 Assistant ExaminerRussell E. Adams, Jr, Patented 1971 Attorney-Nienow & Frater [73] Assignee Symbolic Displays, Inc.

Orange, Calif.

ABSTRACT: This invention relates to improvements in lamp holders and assembly of lamp holders and edge-lighted panels. ln the embodiment illustrated, the lamp is housed in a lamp positioner having conformations to hold the lamp leads with a [54] Fi given orientation relative to the filament of the lamp. These g conformations, and the lamp leads they hold, fit in comple- [52] US. Cl 240/1 EL, mentally formed recesses in a light-receiving member or light 2 /2L240/8J6 filter in engagement with conductor leads embedded in the [51] Int. Cl Bq 3/04 light receiver and exposed at those complementary formed [50] Field ofseal'cll 240/1 El, conformations, The light receiver is provided with a skirt forming a recess within which the lamp positioner is housed. The recess of the light receiver is closed by an end cap of [56] Reierences cued which bears, through a bias spring, upon the lamp positioner UNITED STATES PATENTS to insure contact between the lamp leads and the conductor 3,450,870 6/ 1969 Curl 240/ 1 El leads of the light receiver. An incompletely metallized layer of 3,065,335 11/1962 Madansky 240/1 X material overlying the light receiver reflects some of the light 3,132,81 l 5/ 1964 Madansky 240/1 X emanating from the lamp and permits passage of other light.

k I a/ ILV 32 4/ 4a 74 PATENTEUUET 5191:

IN VE N TOR. 6279442 A. 6024 lrraw/vsrs LAMP HOLDERS This invention relates to improvements in lamp holders. It relates particularly to lamp holders of a type which are suitable for mounting on electric circuit boards and for illuminating Light-conducting plates.

An object of the invention is to provide a new and improved lamp holder. Another object is to provide a lamp holder which permits ready replacement of its bulb. Other objects are to provide a lamp holder which can be used with circuit board or conventional construction, which is useful in illuminating edge lighted panels and annunciators and display devices of various kinds, which can be relamped without soldering and without tools and without danger to the circuitry with which it is associated. Another object is to provide a lamp holder arranged so that replacement lamps will have their filaments oriented in the same direction as that of the lamp being replaced. In this connection it is an object of the invention to provide a lamp holder in which the degree in which the lamp can tilt from its preferred orientation is independent of the accuracy of manufacture of those portions of the lamps whose function is to assure contact with the lamp terminals.

The invention is not limited to lamp holders for lamps of the kind which have conducting lead wires extending from the lamp base. However, it is particularly well suited as a holder for such lamps. Accordingly, The lamp holder selected for illustration in the drawing is specifically arranged for holding such lamps. In the case of very small lamps, the amount of light produced is minimum and measures are advantageously taken to utilize the emitted light in maximum possible degree. Especially in cases of edge-lighted panels, it is desirable to orient the lamp so that the plane in which the filament lies is broadside to the direction in which most illumination is desired.

Lamp holders embodying the invention assure proper orientation of replacement lamps. In this connection, another object is to provide a lamp holder that will pennit mounting a lamp directly under indicia to be lighted without illuminating that indicia excessively relative to indicia located at a distance. A further object is to provide a lamp whose conductive elements are inaccessible when the lamp is assembled in a panel.

It is also an object of the invention to provide a lamp holder which is relatively inexpensive to produce in that relatively inexpensive materials and fabrication techniques are employed.

These, and other objects and advantages of the invention which will hereinafter appear, are realized in part by the provision of a lamp holder comprising a light receiver of light-conducting material formed with a lamp opening to accommodate the lamp and pair of cutouts or conformations extending in different directions from the lamp opening; by the provision of a pair of conductor leads disposed one in each said cutouts or conformations; by the provision of a lamp positioner having a central lamp base receiving opening or recess and having a pair of extensions or conformations shaped to complement the cutouts or confonnations of the light receiver and which is also formed with conformations to accommodate conductive leads extending from the region of the lamp base to said extensions; and by provision of holding means for holding the lamp positioner fixed with its central opening such that a circuit is completed from the lamp to the conductor leads of the light receiver at the point of the lamp positioner extensions. The invention can be otherwise summarized including that it incorporates a light receiver structure formed with a recess opening at one of its faces, and that is also includes a plug or cap which might be formed with a recess in one end face, and that includes a means for assembling the cap in the light receiver such that a cavity is formed by the recess of the light receiver or by the recess of both of them if the cap also includes a recess. The cap is made movable relative to the light receiver to change the size of that cavity. A pair of spaced terminal leads extend to the interior of that cavity and there overlie an area of the interior surface of the light receiver. A lamp positioner is disposed within the cavity and is formed with confor mations or extensions in which lamp conductor elements are disposed and by which they are made to engage the terminal leads extending into the cavity when the lamp positioner is urged in a direction such that the conductors held in its conformations are pressed into engagement with the terminal leads.

In the drawing FIG. I is an isometric view of a fragment of an edge-lighted panel in which a lamp holder embodying the invention is mounted;

FIG. 2 is a cross-sectional view of a fragment of an edgelighted panel overlying a circuit board, as in the construction of FIG. 1, in which a lamp holder according to the invention is shown in side elevation;

FIG. 3 is a cross-sectional view taken on a vertical plane through the lamp holder which contains the filament of the lamp and the conductor leads of the lamp and of the holder;

FIG. 4 is a cross-sectional view of the lamp positioner incorporated in the assembly of FIG. 1;

FIG. 5 is a view in cross section of an assembly comprising the lamp, lamp positioner, and the top portion of the lamp holder of FIG. 3;

FIG. 6 is a top plan view of the lamp positioner of FIG. 4; and

FIG. 7 is a diagram illustrating the relative intensity of light radiated in a plane extending through the filament and normal to the lamp axis of a lamp of the kind shown in FIGS. 3 and 5.

Referring to FIG. I of the drawing, the light plate and lamp holder assembly shown in this drawing is generally designated by the reference number 10. The light plate assembly comprises a plate 12 of transparent or translucent material such for example an acrylic plastic. Such plates are often called panels or edge-lighted panels. The upper surface of the plate 12 is provided with a layer 14 of paint or other opaque material except at points where the paint is omitted to define indicia to be illuminated. An example is the indicia 16 shown in FIG. I. The lower face of the light plate assembly is covered by an electric circuit board 18. The upper face of board 18 is coated in selected areas, and along selected circuit paths, with a conductive material a part of which is visible in FIG. 1 at the region designated 20 where the lower face of the plate 12 is recessed to accommodate a lamp-holder assembly 22. All but the light-shielding washer 24 of the lamp-holder assembly 22 is shown in side elevation in FIG. 2.

The assembly includes a light receiver 26 the lower portion 28 of which has a function separate from the upper portion. The lower portion is called the skirt. The assembly also includes two conductor leads extending in opposite direction from the light receiver portion and designated by the reference numerals 30 and 32, respectively. The light receiver is often called a filter although this term is not necessarily descriptive of its function. It is made of a transparent or translucent material through which light can traverse from the lamp into the light plate or panel 12. In this embodiment the upper face of the light receiver 26 is covered with a layer 34 of material which is coated with a partially reflecting material.

It is not essential that the lamp holder be cylindrical. However this construction is most convenient and comprises the preferred embodiment. The purpose of the lamp holder is to support a lamp, in particular an incandescent lamp as shown, and to provide a means for making electrical contact with the terminals of the lamp. The lamp shown in FIG. 3 is the type designated MS 90451 by the National Electrical Manufacturers Association. That lamp is about one-eighth of an inch in diameter and one embodiment of lamp holder depicted in FIG. 3 has a light receiver 12 of approximately one-third of an inch in diameter.

The lamp is designated generally by the reference number 36. It includes a bulb 38 formed with cylindrical sides and a spherical upper end. Filament 40 is a free standing coil of resistance wire extending between a pair of tenninal wires 41 and 42 which project from the bulb and are bent in opposite directions parallel with the flat base portion of the bulb immediately upon emerging from the bulb. The base end of the bulb fits in a lamp positioner 44 shown in top elevation in FIG. 6 and in cross section in FIG. 4. It comprises a generally cylindrical sleeve having parallel inner wall 45 and outer wall 46. At its upper end the lamp positioner is provided with a pair of spaced projections which are diametric in this embodiment. The leftmost one of these projections is designated by the reference numeral 47 and the rightmost projection is designated by the reference numeral 48. The lamp positioner is provided with conformations in its several walls and its projections. Those conformations are adapted to receive the lead wires of the lamp. They include a recess in the lower face of the positioner which is defined by the wall designated 49. They include a pair of passageways 50 extending from the lower part to the upper part of the cylindrical positioner and they include the slots 51 which are formed in the extensions 47 and 48. These slots have width to accommodate the lead wires 41 and 42 of the lamp but they are less deep then the lamp leads have diameter and will, therefore, have a portion lying above the upper face of the lamp positioner when assembled with the positioner, as best shown in FIG. 5. The lamp positioner is made of an electrically nonconductive material and the lamp is assembled with it by being inserted upwardly through its central opening while having its leads 41 and 42 forced through the openings 50. When the lamp bulb is forced upwardly so that only a space is retained in the lamp positioner, the lead wires are forced against the face of the base of the lamp and into the openings 50. The upper ends are bent over into the slots 51. Each lead wire is bent over at the bulb base in the direction away from the other lead wire. This results automatically in an assembly of the lamp and lamp positioner such that the laterally extending extreme ends of the lead wires 41 and 42 lie in a plane containing the filament 40. The diagram of FIG. 7 illustrates that the intensity of emitted light is maximum in the direction broadside to the filament. The line 52 represents the locus of points along which the intensity of emitted light has reference value.

The light receiver 26 serves to protect the bulb 38 of the lamp and to keep it oriented against tilting. In addition, the light receiver receives light rays from the lamp and controls their distribution. The preferred receiver material is acrylic plastic and is the material employed in this embodiment. In addition to receiving and redirecting the light rays the light receiver forms a base on which the conductor leads are mounted. In this embodiment the conductor leads are embedded in the light receiver by being molded in the plastic of which the receiver is formed. The conductor leads 30 and 32 may be formed of tinned copper as shown. They are generally S-shaped each having a laterally disposed portion approximately at the horizontal midplane of the unit. This portion of conductor 30 is designated by the reference numeral 60 and the corresponding portion of the conductor 32 is designated 61. The lower face of these two portions 60 and 61 are exposed to a recess formed in the lower face of the light receiver 12. The recess has a large diameter so that only downwardly extending angular skirt 28 remains at the lower end of the light receiver. The portions 60 and 61 of the two conductor wires fit in conformations formed on the inner surface of that light receiver recess. A portion of the conformation in which end 60 of conductor 30 is disposed is visible in FIG. 3 where it is designated by reference numeral 62. At the other side, end 61 of conductor 32 fits into a conformation 63. The extension 48 of the lamp positioner also fits within the conformation 63. Similarly extension 47 fits within the conformation 62. Being so fitted, the lamp conductor wires carried by these extensions are placed in contact with a respectively associated one of the conductor leads 30 and 32.

Means are provided in the invention for maintaining the conductor leads in contact with the lamp leads. Thus means are provided in this embodiment for maintaining the conductor end 61 in contact with lamp lead 41 and for maintaining end 60 of conductor 30 in contact with lamp lead 42. In preferred form this means includes means for maintaining that contact through the medium of a resilient bias. In this embodiment that means is provided by a cap 70 which is threaded into the skirt 28 of the light receiver. An internally threaded ring 72 is fitted within the recess at the lower face of the light receiver. This threaded ring 72 has outside diameter to fit within the skirt 38 and it is retained there by another ring 74 of readily deformable adhesive material. The cap 70 has external threads which mate with the threads of the threaded ring 72. In preferred form the cap 70 has a recess in its upper face which forms a cavity in which the lamp positioner is disposed when the cap 70 is assembled with the light receiver 26. At it supper face the cap 70 is provided with an inwardly turned lip 76 having inside diameter substantially equal to the outside diameter of the lamp positioner wall 46. Adjacent to its lower face the lamp positioner is provided with an upwardly extending flange or lip 78. Lip 78 has a diameter greater than outside wall 46 of the retainer. Thus the outside diameter of the lip 78 is greater then the inside diameter of the cap lip 76. However, the lamp positioner is formed of a plastic material that will deform and return to an original shape. It is easily pressed into the recess of cap 70. Having been so asembled, its lip 78 will return to original shape and will underlie the lip 76 of the cap. Thus the lamp positioner and cap are interfitted in telescoping fashion whereby the lamp positioner is free to telescope into and out of the cap recess.

Means are provided for biasing the lamp positioner toward its extended position as shown in FIG. 5. This means may comprise a warped disc of spring material such as the disc 80 in FIG. 5. A thin layer of insulating material 82 is trapped in the recess of the cap between the upper face of the spring disc 80 and the lamp leads 41 and 42 to prevent the leads from becoming short circuited by the spring. When the unit is assembled, cap 70 is screwed into the threaded ring 72 until the spring 80 is flattened whereby the full force of the spring is employed to force the lamp positioner upwardly toward the upper face of the unit. This forces the lamp lead wires 41 and 42 into contact with the parts 61 and 62, respectively, of the two conductor leads 32 and 30. The cap 70 may be provided with a kerf 84, as shown to facilitate screwing the cap into the threaded ring 72 and removing it therefrom.

To replace a lamp it is necessary only to remove the cap 70 by screwing it away from the light receiver. This is readily done because the cap 70 rotates relative to the lamp positioner. The latter is precluded from rotating relative to the lamp receiver but can be withdrawn axially from the receiver recess. The lamp positioner is removed with the cap 70. Upon removal the assembly has the form illustrated in FIG. 5. The lamp positioner is easily pried loose from the cap to permit replacement of the lamp. After the lamp is replaced the unit may be reassembled in the reverse process.

In the completely assembled lamp holder, as shown in FIG. 3, the filament of the lamp is at a point opposite of the upper portion of the light receiver. Light emanating from the lamp enters the light receiver and is there filtered, redirected or otherwise treated. In this embodiment the light receiver is simply a cylindrical body of clear plastic to pass white light covered by a special semireflective layer 34. This special layer comprises a disc of metallized plastic. The metallizing is sufi'iciently thin so that an appreciable quantity of light is transmitted upwardly through the layer. However the remainder of the light is reflected by the metallized surface and remains within the light receiver 26. Use of this semireflective layer has several advantages which may be understood by an examination of FIG. 1 and 2. For example, it permits placement of the lamp holder directly under an indicia to be lighted without unduly increasing the intensity of the light from that indicia relative to the light that emanates from the other indicia in the same edge-lighted panel. Referring to FIG. 2. the fact that there is a partially reflective layer directly over the lamp results in reflection through the light receiver and into the light-conducting panel 12 at an elevational level which is lower then would be true if a reflection along the panel depended upon a reflective surface at the upper layer 14. The

- result is that light can be transmitted effectively over greater distances within the light panel.

To prevent the escape of light from the lower face of the light panel though the space between the outer wall of the lamp holder and the wall that defines the recess in which it is placed, the invention contemplates the use of a washer tightly encircling the lamp holder to prevent the loss of light around the holder. In this embodiment the washer comprises a spring washer which serves to hold the conductor leads 30 and 32 tightly against the inner or upper conductive face of the electrical circuit board 18. The spring washer is made of a nonconductive material so is otherwise constructed so that it will not short circuit the two conductor leads. To accommodate that washer and the conductor leads the recess 90 of the light plate is enlarged as at 92 at the lower face of the light plate.

Although I have shown and described certain specific embodiments of my invention, 1 am fully aware that many modifications thereof are possible. My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

l claim:

1. For a lamp and lamp-holder assembly of the type in which a pair of conductor leads extend in different directions from the base of the lamp, a lamp holder comprising, in combination;

a light receiver formed with a recess opening at one of its faces;

a cap formed with a recess in one end face;

means for assembling and removably retaining said cap in the light receiver such that a cavity is formed jointly by their respective recesses, the size of said cavity being variable as an incident to change in position of the cap relative to the light receiver;

a pair of spaced terminal leads extending through said receiver to the interior thereof and there overlying respectively associated areas of the receiver surface defining said recess of the light receiver;

lamp-positioning means comprising a lamp positioner disposed within said cavity and shaped to receive the base of a lamp and lamp conductor wires at points opposite said areas of the receiver surface, said lamp positioner having size permitting motion thereof within said cavity toward and away from said areas of the receiver in one position of the cap relative to the receiver and precluding motion away from said areas in another position of the cap relative to the receiver;

in which said lamp positioner and the recessed surface of said light receiver are provided with means, in the form of surfaces defining a cutout in one of them and a projection on the other of them of size to fit within said cutout, for limiting motion of said lamp positioner, when assembled therewith, to motion carrying said lamp positioner toward and away from said areas of the light receiver.

2. The invention defined in claim 1 which further comprises spring means disposed in said cavity for biasing said lamp positioner in a direction toward said tenninal leads.

3. The invention defined in claim 2 in which said cap is cylindrical, its recess being formed axially in one end face thereof; said lamp positioner comprising a sleeve of electrically nonconductive material telescopically disposed within said axial recess of the cap.

4. The invention defined in claim 3 in which said light receiver is formed with a central opening communicating with said recess of said light receiver, the opening having dimensions to accommodate the base of a lamp.

5. The invention defined in claim 4 which further comprises a reflective and translucent layer of metallized material overlying said cavity of said light receiver whereby a quantity of light from said lamp is transmitted through said layer of material, the remainder of the light being reflected therefrom.

6. The invention defined in claim 4 which further comprises means for trapping said sleeve within the recess of said cap and preventing disassembly of said sleeve and cap a an incident to action of said means for biasing the lamp positioner in a direction toward said terminal leads.

7. For a lamp and lampholder assembly of the type in which a pair of conductor leads extend in different directions from the base of the lamp, a lamp holder comprising, in combination:

a light receiver formed with a recess opening at one of its faces;

a cap formed with a recess in one end face;

means for assembling and removably retaining said cap in the light receiver such that a cavity is formed jointly by their respective recesses, the size of said cavity being variable as an incident to change in position of the cap relative to the light receiver;

A pair of spaced terminal leads extending through said receiver to the interior thereof and there overlying respectively associated areas of the receiver surface defining said recess of the light receiver;

lamp-positioning means comprising a lamp positioner disposed within said cavity and shaped to receive the base of a lamp and lamp conductor wires at points opposite said areas of the receiver surface, said lamp positioner having size permitting motion thereof within said cavity toward and away from said areas of the receiver in one position of the cap relative to the receiver and precluding motion away from said areas in another position of the cap relative to the receiver;

said lamp positioner and the recessed surface of said light receiver being provided with means in the form of surfaces defining a cutout in one of them and a projection on the other of them of size to fit within said cutout, for limiting motion of said lamp positioner, when assembled therewith, to motion carrying said lamp positioner toward and away from said areas of the light receiver;

spring means disposed in said cavity for biasing said lamp positioner in a direction toward said terminal leads;

said cap being cylindrical, its recess being formed axially in one end face thereof; said lamp positioner comprising a sleeve of electrically nonconductive material telescopically disposed within said axial recess of the cap;

said light receiver being formed with a central opening communicating with said recess of said light receiver, the opening having dimensions to accommodate the base of a lamp;

means for trapping said sleeve within the recess of said cap and preventing disassembly of said sleeve and cap as an incident to action of said means for biasing the lamp positioner in a direction toward said terminal leads; in which said sleeve of nonconducting material comprising the lamp positioner is formed with a pair of passageways, each having a size to accommodate one of the leads from a lamp, extending the region of one end of said sleeve to a point adjacent to the other end thereof and opening at said conformations shaped to receive lamp conductor wires.

8. A lamp holder for a lamp of the type having conducting leads extending from its base comprising:

a light receiver of light-conducting material formed with a lamp opening of size to accommodate a lamp and a pair of cutouts extending in different directions from the lamp opening;

a pair of conductor leads disposed one in each of said cutouts;

a lamp positioner having a central lamp base-receiving opening, having a pair of extensions shaped to fit within said cutouts, and formed to accommodate said extensions to fit the conducting leads of a lamp; and

holding means for holding the lamp positioner fixed with its central opening in alignment with the lamp opening of the light receiver and with its extensions disposed in respec tively associated ones of said cutouts.

9Q The invention defined in claim 8 in which said holding means comprises a cylindrical cap fixed to said light receiver,

said lamp positioner and said retention member being telescoped one within the other; and

which further comprises means for urging said lamp positioner and said cap to relatively extended position such that said extensions of the lamp positioner are urged into the cutouts of the light receiver.

10. The invention defined in claim 9 in which said light receiver is fonned with an internally threaded cylindrical skirt and said retention member comprises as externally threaded plug threadedly engaged within said skirt.

11. The invention defined in claim 10 which further comprises a plate of light-conducting material having a recess formed in one face thereof of size to accommodate said light receiver of said lamp holder; and a circuit board overlying said one face of the plate and having an opening to accommodate said skirt of said light receiver, said circuit board comprising electrically isolated, conductive surfaces and said plate, lamp holder, and circuit board being assembled with said light receiver fitted into said opening of the plate and said pair of conductor leads overlying said one surface of said plate and said circuit board overlying said pair of conductor leads such that said conductor leads are an electrical communication with respective ones of said conductive surfaces of the circuit board; said circuit board being arranged with its opening in alignment with the opening of said plate and said holding means and having size to permit removal of said holding means and said lamp positioner through said opening in the circuit board.

12. The invention defined in claim 11 which further comprises a washer of opaque material encircling said light receiver and interposed between said plate and said pair of conductor leads. 

1. For a lamp and lamp-holder assembly of the type in which a pair of conductor leads extend in different directions from the base of the lamp, a lamp holder comprising, in combination; a light receiver formed with a recess opening at one of its faces; a cap formed with a recess in one end face; means for assembling and removably retaining said cap in the light receiver such that a cavity is formed jointly by their respective recesses, the size of said cavity being variable as an incident to change in position of the cap relative to the light receiver; a pair of spaced terminal leads extending through said receiver to the interior thereof and there overlying respectively associated areas of the receiver surface defining said recess of the light receiver; lamp-positioning means comprising a lamp positioner disposed within said cavity and shaped to receive the base of a lamp and lamp conductor wires at points opposite said areas of the receiver surface, said lamp positioner having size permitting motion thereof within said cavity toward and away from said areas of the receiver in one position of the cap relative to the receiver and precluding motion away from said areas in another position of the cap relative to the receiver; in which said lamp positioner and the recessed surface of said light receiver are provided with means, in the form of surfaces defining a cutout in one of them and a projection on the other of them of size to fit within said cutout, for limiting motion of said lamp positioner, when assembled therewith, to motion carrying said lamp positioner toward and away from said areas of the light receiver.
 2. The invention defined in claim 1 which further comprises spring means disposed in said cavity for biasing said lamp positioner in a direction toward said terminal leads.
 3. The invention defined in claim 2 in which said cap is cylindrical, its recess being formed axially in one end face thereof; said lamp positioner comprising a sleeve of electrically nonconductive material telescopically disposed within said axial recess of the cap.
 4. The invention defined in claim 3 in which said light receiver is formed with a central opening communicating with said recess of said light receiver, the opening having dimensions to accommodate the base of a lamp.
 5. The invention defined in claim 4 which further comprises a reflective and translucent layer of metallized material overlying said cavity of said light receiver whereby a quantity of light from said lamp is transmitted through said layer of material, the remainder of the light being reflected therefrom.
 6. The invention defined in claim 4 which further comprises means for trapping said sleeve within the recess of said cap and preventing disassembly of said sleeve and cap a an incident to action of said means for biasing the lamp positioner in a direction toward said terminal leads.
 7. For a lamp and lampholder assembly of the type in which a pair of conductor leads extend in different directions from the base of the lamp, a lamp holder comprising, in combination: a light receiver formed with a recess opening at one of its faces; a cap formed with a recess in one end face; means for assembling and removably retaining said cap in the light receiver such that a cavity is formed jointly by their respective recesses, the size of said cavity being variable as an incident to change in position of the cap relative to the light receiver; A pair of spaced terminal leads extending through said receiver to the interior thereof and there overlying respectively associated areas of the receiver surface defining said recess of the light receiver; lamp-positioning means comprising a lamp positioner disposed within said cavity and shaped to receive the base of a lamp and lamp conductor wires at points opposite said areas of the receiver surface, said lamp positioner haVing size permitting motion thereof within said cavity toward and away from said areas of the receiver in one position of the cap relative to the receiver and precluding motion away from said areas in another position of the cap relative to the receiver; said lamp positioner and the recessed surface of said light receiver being provided with means in the form of surfaces defining a cutout in one of them and a projection on the other of them of size to fit within said cutout, for limiting motion of said lamp positioner, when assembled therewith, to motion carrying said lamp positioner toward and away from said areas of the light receiver; spring means disposed in said cavity for biasing said lamp positioner in a direction toward said terminal leads; said cap being cylindrical, its recess being formed axially in one end face thereof; said lamp positioner comprising a sleeve of electrically nonconductive material telescopically disposed within said axial recess of the cap; said light receiver being formed with a central opening communicating with said recess of said light receiver, the opening having dimensions to accommodate the base of a lamp; means for trapping said sleeve within the recess of said cap and preventing disassembly of said sleeve and cap as an incident to action of said means for biasing the lamp positioner in a direction toward said terminal leads; in which said sleeve of nonconducting material comprising the lamp positioner is formed with a pair of passageways, each having a size to accommodate one of the leads from a lamp, extending the region of one end of said sleeve to a point adjacent to the other end thereof and opening at said conformations shaped to receive lamp conductor wires.
 8. A lamp holder for a lamp of the type having conducting leads extending from its base comprising: a light receiver of light-conducting material formed with a lamp opening of size to accommodate a lamp and a pair of cutouts extending in different directions from the lamp opening; a pair of conductor leads disposed one in each of said cutouts; a lamp positioner having a central lamp base-receiving opening, having a pair of extensions shaped to fit within said cutouts, and formed to accommodate said extensions to fit the conducting leads of a lamp; and holding means for holding the lamp positioner fixed with its central opening in alignment with the lamp opening of the light receiver and with its extensions disposed in respectively associated ones of said cutouts.
 9. The invention defined in claim 8 in which said holding means comprises a cylindrical cap fixed to said light receiver, said lamp positioner and said retention member being telescoped one within the other; and which further comprises means for urging said lamp positioner and said cap to relatively extended position such that said extensions of the lamp positioner are urged into the cutouts of the light receiver.
 10. The invention defined in claim 9 in which said light receiver is formed with an internally threaded cylindrical skirt and said retention member comprises as externally threaded plug threadedly engaged within said skirt.
 11. The invention defined in claim 10 which further comprises a plate of light-conducting material having a recess formed in one face thereof of size to accommodate said light receiver of said lamp holder; and a circuit board overlying said one face of the plate and having an opening to accommodate said skirt of said light receiver, said circuit board comprising electrically isolated, conductive surfaces and said plate, lamp holder, and circuit board being assembled with said light receiver fitted into said opening of the plate and said pair of conductor leads overlying said one surface of said plate and said circuit board overlying said pair of conductor leads such that said conductor leads are an electrical communication with respective ones of said conductive surfaces of the circuit board; said circuit board beIng arranged with its opening in alignment with the opening of said plate and said holding means and having size to permit removal of said holding means and said lamp positioner through said opening in the circuit board.
 12. The invention defined in claim 11 which further comprises a washer of opaque material encircling said light receiver and interposed between said plate and said pair of conductor leads. 